This invention relates to 1, 2, 3, 4 tetrahydroquinoline derivatives, to processes for their preparation, to pharmaceutical compositions containing them and to their use in medicine. In particular, it relates to 1, 2, 3, 4 tetrahydroquinoline derivatives which are potent and specific antagonists of excitatory amino acids.
Carling et al., Bioorganic and Medicinal Chemistry Letters, Vol. 13 pp. 65-70, 1993, teaches 4-substituted-2-carboxy tetrahydroquinolines having good in vitro affinity for the glycine modulatory site of the NMDA receptor complex but at best only weak in vivo activity. More particularly, it teaches that such derivatives substituted at the 4 position by the group CH2CO2H or CH2CONHPh have little or no in vivo activity when administered systemically (ip).
WO 97/12870 and WO 98107704 describe novel 4-substituted-2-carboxy-tetrahydroquinoline derivatives which not only have a good in vitro affinity for the strychnine insensitive glycine binding site associated with the NMDA receptor complex but also have good in vivo activity when administered intravenously (iv).
We have now discovered a novel group of 4-substituted-2-carboxy tetrahydroquinoline having a particularly useful profile of activity as selective antagonists for the strychnine insensitive glycine binding site associated with the NMDA receptor complex.
Thus the present invention provides a compound of formula (I) 
or a salt or a non toxic metabolically labile esters thereof, wherein
Y represents a carbon atom;
Z is the group CH which is linked to the group Y via a double bond and
X is CH or Z is methylene or NR11 and X is a carbon atom linked to the group Y via a double bond;
A represents a C1-2alkylene chain and which chain may be substituted by one or two groups selected from C1-6alkyl optionally substituted by hydroxy, amino, C1-4 alkyl amino or C1-4dialkyl amino or which chain may be substituted by the group=0;
R represents a halogen atom or C1-4alkyl group;
R1 represents a hydrogen, a halogen atom or C1-4alkyl group;
R2 represents phenyl which may be substituted with up to 3 groups selected from halogen, hydrogen, or (CH2)nR3 wherein R3 is COR4, NR6R5, NHCOR7, NHCONR9R8 or NH SO2 R10 group or R2 is a 5 membered heteroaryl group containing 1 to 3 heteroatoms selected from oxygen, sulphur and nitrogen; or 6 membered heteroaryl group containing 1 to 3 nitrogen atoms
R4 represents an amino, a hydroxyl or C1-4 alkoxy group;
R5 and R6 each independently represents hydrogen or C1-4 alkyl group or
R5 and R6 together with the nitrogen atom to which they are attached represent a saturated 5-7 membered heterocyclic group optionally containing an additional heroatom selected from oxygen,sulphur or nitrogen
R7 represents a hydrogen atom or C1-4 alkyl, C1-4 alkoxy, or phenyl;
R8 represents hydrogen or C1-4 alkyl group;
R9 represents hydrogen, optionally substituted C1-4 alkyl (optionally substituted by one or more hydroxy carboxyl and amino group), phenyl;
R11 represents hydrogen or C1-4 alkyl group;
R10 represents hydrogen, C1-4 alkyl or a nitrogen protecting group.
n is zero or an integer from 1 to 2;
A further embodiment of the invention provides compounds of formula(I)or a salt or a non toxic metabolically labile esters thereof, wherein
Y represents a carbon atom;
Z is the group CH which is linked to the group Y via a double bond and
X is CH or Z is methylene or NR11 and X is a carbon atom linked to the group Y via a double bond;
A represents a C1-2 alkylene chain and which chain may be substituted by one or two groups selected from C1-4 alkyl optionally substituted by hydroxy, amino, C1-4 alkyl amino or C1-4 dialkyl amino or which chain may be substituted by the group=0;
R represents a halogen atom;
R1 represents a hydrogen or a halogen atom;
R2 represents phenyl which may be substituted with up to 3 groups selected from halogen, hydrogen, or (CH2)nR3 wherein R3 is COR4, NR6R5, NHCOR7, NHCONR9R8 or NH SO2 R10 group or R2 is a 5 membered heteroaryl group containing 1 to 3 heteroatoms selected from oxygen, sulphur and nitrogen; or 6 membered heteroaryl group containing 1 to 3 nitrogen atoms
R4 represents an amino or a hydroxyl;
R5 and R6 each independently represents hydrogen or C1-4 alkyl group or
R5 and R6 together with the nitrogen atom to which they are attached represent a saturated 5-7 membered heterocyclic group optionally containing an additional heroatom selected from oxygen,sulphur or nitrogen
R7 represents a hydrogen atom or C1-4, alkyl, C1-4 alkoxy, or phenyl;
R8 represents hydrogen or C1-4 alkyl group;
R9 represents hydrogen, optionally substituted C1-4 alkyl (optionally substituted by one or more hydroxy carboxyl and amino group), phenyl;
R11 represents hydrogen or C1-4 alkyl group;
R10 represents hydrogen, C1-4 alkyl or a nitrogen protecting group;
n is zero or an integer from 1 to 2 with the proviso that when X is a carbon atom linked to the group Y via a double bond then R1 is hydrogen;
For use in medicine the salts of the compounds of formula (I) will be physiologically acceptable thereof. Other salts however may be useful in the preparation of the compounds of formula (I) or physiologically acceptable salts thereof. Therefore, unless otherwise stated, references to salts include both physiologically acceptable salts and non-physiologically acceptable salts of compounds of formula (I).
Suitable physiologically acceptable salts of compounds of the invention include base addition salts and, where appropriate, acid addition salts. Suitable physiologically acceptable base addition salts of compounds of formula (I) include alkali metal or alkaline metal salts such as sodium, potassium, calcium, magnesium and ammonium salts, formed with amino acids (e.g. lysine and arginine) and organic bases (e.g. procaine, phenylbenzylamine, ethanolamine diethanolamine and N-methyl glucosamine).
The compounds of formula (I) and/or salts thereof may form solvates (e.g. hydrates) and the invention includes all such solvates.
The term halogen refers to a fluorine, chlorine, bromine or iodine atom.
The term C1-4 alkyl as used herein as a group or part of a group refers to a straight or branched chain alkyl group containing from 1 to 4 carbon atom, examples of such groups include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, secondary butyl or tertiary butyl.
When R2 is a 5 or 6 membered heteroaryl group this may be for example furanyl, thiophenyl, imidazolyl, thiazolyl, oxazolyl, pyridyl or pyrimidinyl.
When R5 and R6 together with the nitrogen atom to which they are attached form a saturated 5-7 membered heterocyclic group optionally containing an additional heroatom selected from oxygen, sulphur or nitrogen this may be morpholino, 2,6 dimethylmorpholino, thiomorpholino, piperidino, pyrrolidino, piperazino or N-methylpiperazino.
When R2 is a substituted phenyl group this is conveniently a mono substituted phenyl group. The substituent is conveniently in the meta position or more conveniently in the para position.
When Xxe2x80x94Y represents a double bond, the compounds of formula (I) possess at least one asymmetric carbon atom (namely the carbon atom occupying the 2 position of the 1, 2, 3, 4 tetrahydroquinoline ring system) and other asymmetric carbon atoms are possible in the group R2. It is to be understood that all enantiomers and diastereomers and mixtures thereof are encompassed within the scope of the present invention.
When Xxe2x80x94Y represents a single bond, the compounds of formula (I) possess at least two asymmetric carbon atoms (namely the carbon atom occupying the 2 and 4 position of the 1, 2, 3, 4 tetrahydroquinoline ring system) and these may be represented by the formulae (1a, 1b, 1c and 1d). 
The solid wedge shaped bond indicates that the bond is above the plane of the paper and is referred to as the xcex2 configuration. The broken indicates that the bond is below the plane of the paper and is referred to as xcex1 configuration.
Further other asymmetric carbon atoms are possible in the groups R2. It is to be understood that all enantiomers and diastereomers and mixtures thereof are encompassed within the scope of the present invention.
Nonoxic metabolically labile esters of compound of formula (I) are esters of compounds of formula (I) that are hydrolysed in vivo to afford said compound of formula I and a physiologically acceptable alcohol. Non toxic metabolically esters of compound of formula (I) may be formed by esterification, for example of any of the carboxylic acid groups in the parent compound of general formula (I) with, where appropriate, prior protection of any other reactive groups present in the molecule, followed by deprotection if required. Examples of such metabolically labile esters include C1-4alkyl esters e.g. methyl or ethyl esters, substituted or unsubstituted aminoalkyl esters (e.g. aminoethyl, 2-(N,N-diethylamino) ethyl, or 2-(4-morpholino)ethyl esters or acloxyalkyl esters such as, acyloxymethyl or 1-acyloxyethyl e.g. pivaloyloxymethyl, 1-pivaloyloxyethyl, acetoxymethyl, 1-acetoxyethyl, 1-(1-methoxy-1-methyl)ethylcarbonyloxyethyl, 1-benzoyloxyethyl, isopropoxycarbonyloxymethyl, 1-sopropoxycarbonyloxyethyl, cyclohexylcarbonyloxymethyl, 1-cyclohexylcarbonyloxyethyl ester, cyclohexyloxycarbonyloxymethyl, 1-cyclohexyloxycarbonyloxyethyl, 1-(4-tetrahydropyranyloxy)carbonyloxyethyl or 1-(4-tetrahydropyranyl)carbonyloxyethyl.
The group R is conveniently chlorine.
The group R1 is conveniently a hydrogen or a chlorine atom.
A preferred class of compounds of formula(I) is that wherein R is chlorine and R1 is a hydrogen or a chlorine atom.
A further preferred class of compounds of formula(I) is that wherein R is chlorine and R1 is a hydrogen atom.
When Xxe2x80x94Y is a single bound, a preferred class of compounds of formula (1) is that in which the carbon atom in 4 position is xcex2 configuration and the carbon atom in 2 positlon is in a configuration (1a) and that in which the carbon atom in 4 position is a configuration and the carbon atom in 2 position is in xcex2 configuration (1c).
When A is an optionally substituted C1-2 alkylene chain this may be, for example, methylene, ethylene or Cxe2x95x90O.
A preferred class of compounds of formula (I) includes those wherein A is a chain selected from xe2x80x94CH2xe2x80x94, xe2x80x94(CH2)2xe2x80x94, Cxe2x95x90O.
When Z is a group NR11 this is conveniently the group NH.
A preferred class of compounds of formula (I) includes those wherein Z is CH which is linked to the group Y via a double bond a methylene or a NH group.
When R2 is an optionally substituted phenyl group this is conveniently phenyl substituted by a single substituent selected from (CH2)nNR6R5 in which R5 is hydrogen and R6 is hydrogen, C1-4 alkyl (e.g. methyl, ethyl) or NR6R5 represents a saturated 6 membered ring containing oxygen e.g. morpholino; (CH2)nNHCOR7 wherein R7 is hydrogen, alkyl e.g. methyl, isopropyl, isobutyl, phenyl; (CH2)nNHCONHR9 wherein R9 is hydrogen; (CH2)nNH SO2 R10 in which R10 is alkyl e.g. methyl. n is zero or an integer from 1 to 2; Examples of such R2 groups include phenyl (optionally substitued by amino, t-butoxycarbonylamino, acetylamino or methanesulphonylamino).
When R2 is substituted phenyl the substituents are conveniently in the meta or more preferably in the para position.
When R2 is a 5 or 6 membered heteroaryl group as above defined this is conveniently pyridyl e.g. 3-pyridyl.
A preferred class of compounds of formula (I) is that wherein R2 represents phenyl (optionally substituted by acetylamino, methanesulphonylamino) or 3-pyridyl. Within this class those wherein R2 is phenyl are particularly preferred.
A further preferred class of compounds of formula (I) is that wherein X is a carbon atom linked to the group Y via a double bond.
A preferred group of compounds of formula(I) is that wherein A is is a chain selected from xe2x80x94CH2xe2x80x94 or xe2x80x94(CH2)2xe2x80x94, Z is a group CH which is linked to the group Y via a double bond or a methylene group, or A is the chain CO and Z is an NH group, R is chlorine, R1 is chlorine or hydrogen and R2 is phenyl (optionally substitued by acetylamino or methanesulphonylamino) or 3-pyridyl.
Specific preferred compounds of the invention include:
(xc2x1)7-chloro-4-2-oxo-1-phenyl-3-pyrrolidinylidene)-1,2,3,4-tetrahydro-2-quinoline carboxylic acid,
(xc2x1)7-chloro-4-(1-phenyl-xcex943-pyrrolin-2-one-3yl)-1,2,3,4-tetrahydro-2-quinoline carboxylic acid,
and physiologically acceptable salts (e.g. sodium salt) non-toxic metabolically labile esters or enantiomers thereof.
(xe2x88x92)-Sodium 7-chloro-4-(2-oxo-1-phenyl-3-pyrrolidinylidene)-1,2,3,4-tetrahydro-2-quinolinecarboxylate.
(xe2x88x92)Sodium 7-chloro-4(1-phenyl-xcex943-pyrrolin-2-one-3yl)-1,2,3,4-tetrahydroquinoline-2-carboxylate,
(+)Sodium 7-chloro-4-(1-phenyl-xcex943-pyrrolin-2-one-3yl)-1,2,3,4-tetrahydroquinoline-2carboxylate.
Further specific preferred compounds of the invention include:
(xc2x1)-7-chloro-4-(1-(3-pyridin)-xcex943-pyrrolin-2-one-3yl)-1,2,3,4-tetrahydroquinoline-2-carboxylic acid,
(xc2x1)-7-chloro-4-(1-phenylxcex943-5,6-dihydro-pyridin-2-one-3yl)-1,2,3,4-tetrahydroquinoline-2-carboxlic acid,
(xc2x1)-5,7dichloro-4-(1-phenyl-xcex943-pyrrolin-2-one-3yl)-1,2,3,4-tetrahydroquinoline-2carboxylic acid,
(+/xe2x88x92)-7chloro-4-(1-(4-acetylamino)-1-phenyl-xcex943-pyrrolin-2-one-3yl)-1,2,3,4-tetrahydroquinoline-2-carboxylic acid,
(+/xe2x88x92)7-chloro-4(1-(4-methanesulfonylamino)-1-phenyl-xcex943-pyrrolin-2-one-3yl)-1,2,3,4-tetrahydroquinoline-2-carboxylic acid,
(xc2x1)-7-chloro-4-(2-oxo-1-phenyl-3-piperidinylidene)-1,2,3,4-tetrahydro-2-quinolinecarboxylic acid,
(xc2x1)-7-chloro-4-(2,5-dioxo-1-phenyl-imidazolidin-4-ylidene)-1,2,3,4-tetrahydro-2-quinolinecarboxylic acid,
(xc2x1)-7-chloro-4(2-oxo-1-(pyridin-3yl)-pyrrolidin-3-ylidene)-1,2,3,4-tetrahydro-2quinolinecarboxylate,
(xc2x1)-7-chloro-4-(2-oxo-1-(4-acetylamino)phenyl-pyrrolidin-3-ylidene)-1,2,3,4-tetrahydro-2-quinolinecarboxylic acid,
(xc2x1)7-chloro-4-(2-oxo-1((4-methanesulfonyl amino)phenyl-pyrrolidin-3-ylidene)-1,2,3,4-tetrahydro-2-quinolinecarboxylic acid,
5,7-dichloro-4-(2-oxo-1-(phenyl)-pyrrolidin-3-ylidene)-1,2,3,4-tetrahydro-2quinoline carboxylic acid(enantiomer A);
5,7-dichloro-4-(2-oxo-1-phenyl-xcex943-pyrrolin-2-one-3-yl)1,2,3,4-tetrahydroquinoline-2-carboxylic acid (enatiomer A);
and physiologically acceptable salts (e.g. sodium salts), non-toxic metabolically labile esters or enantiomers thereof.
The compounds of formula (I) and/or physiologically acceptable salts thereof are excitatory amino acid antagonists. More particularly they are potent antagonists at the strychnine insensitive glycine binding site associated with the NMDA receptor complex. As such they are potent antagonists of the NMDA receptor complex. These compounds are therefore useful in the treatment or prevention of neurotoxic damage or neurodegenerative diseases. Thus the compounds are useful for the treatment of neurotoxic injury which follows cerebral stroke, thromboembolic stroke, hemorrhagic stroke, cerebral ischemia, cerebral vasospam, hypoglycemia, amnesia, hypoxia, anoxia, perinatal asphyxia cardiac arrest. The compounds are useful in the treatment of chronic neurodegenerauive diseases such as: Huntingdon""s disease, Alzheimer""s senile dementia, amyotrophic lateral sclerosis, Glutaric Acidaemia type, multi-infarct dementia, status epilecticus, contusive injuries (e.g. spinal cord injury and head injury), viral infection induced neurodegeration (e.g. AIDS, encephalopaties), Down syndrome, ocular neurodegeneration (e.g glaucoma), epilepsy, schizophrenia, depression, migraine, headaches including cluster headaches and or tension headaches, anxiety, pain (e.g inflamatory pain and neuropathic pain), neurogenic bladder, emesis irritative bladder disturbances, drug dependency, including withdrawal symptoms from alcohol, cocaine, opiates, nicotine (e.g. smoking cessation) benzodiazepines and. inhibition of tolerance induced by opioids (i.e morphine).
The potent and selective action of the compound of the invention at the strychnine-insensitive glycine binding site present on the NMDA receptor complex may be readily determined using conventional test procedures. Thus the ability to bind at the strychnine insensitive glycine binding site was determined using the procedure of Kishimoto H et al., J Neurochem 1981, 37, 1015-1024. The selectivity of the action of compounds of the invention for the strychnine insensitive glycine site was confirmed in studies at other ionotropic known excitatory amino acid receptors. Thus compounds of the invention were found to show little or no affinity for the kainic acid (kainate) receptor, a-amino-3-hydroxy-5-methyl-4-isoxazole-proprionic acid (AMPA) receptor or at the NMDA binding site.
Compounds of the invention may be found found to inhibit NMDA induced convulsions in mice using the procedure Chiamulera C et at, Psychopharmacology (1990), 102, 551-552.
The neuroprotective activity of the compounds of the invention may be demonstrated in the middle cerebral artery occlusion preparation in mice, using the procedure described by Chiamulera C. et al., European Journal of Pharmacology, 216 (1992) pp. 335-336.
The ability of compounds of the invention to alleviate withdrawal symptoms from nicotine following smoking cessation may be demonstrated in conventional tests of nicotine induced relapse using the procedure described in C. Chiamulera et al., Arch. Pharmacol., 358, 1998.
The invention therefore provides for the use of a compound of formula (I) and/or physiologically acceptable salts or non-toxic metabolically labile esters thereof for use in therapy and in particular use as medicine for antagonising the effects of excitatory amino acids upon the NMDA receptor complex.
The ability of compounds of the invention to inhibit pain may be demonstrated in conventional analgesic screen such as those described by Dubuisson and Dennis, Pain, 1977, 4:161-174; J. J. Bennett and J. K Xue, Pain, 1988, 41, 87-107.
The invention also provides for the use of a compound of formula (I) and/or a physiologically acceptable salt or non-toxic metabolically labile esters thereof for the manufacture of a medicament for antagonising the effects of excitatory amino acids upon the NMDA receptor complex.
According to a further aspect, the invention also provides for a method for antagonising the effects of excitatory amino acids upon the NMDA receptor complex, comprising administering to a patient in need thereof an antagonistic amount of a compound of formula (I) and/or a physiologically acceptable salt thereof.
It will be appreciated by those skilled in the art that reference herein to treatment extends to prophylactics as well as the treatment of established diseases or symptoms.
It will further be appreciated that the amount of a compound of the invention required for use in treatment will vary with the nature of the condition being treated, the route of administration and the age and the condition of the patient and will be ultimately at the discretion of the attendant physician. In general however doses employed for adult human treatment will typically be in the range of 2 to 800 mg per day, dependent upon the route of administration. Thus for parenteral administration a daily dose will typically be in the range 20-100 mg, preferably 60-80 mg per day. For oral administration a daily dose will typically be within the range 200-800 mg , e.g. 400-600 mg per day.
The desired dose may conveniently be presented in a single dose or as divided doses administered at appropriate intervals, for example as two, three, four or more sub-doses per day.
While it is possible that, for use in therapy, a compound of the invention may be administered as the raw chemical, it is preferable to present the active ingredient as a pharmaceutical formulation.
The invention thus further provides a pharmaceutical formulation comprising a compound of formula (I) or a pharmaceutically acceptable salt or non-toxic metabolically labile esters thereof together with one or more pharmaceutically acceptable carriers thereof and, optionally, other therapeutic and/or prophylactic ingredients. The carrier(s) must be xe2x80x98acceptablexe2x80x99 in the sense of being compatible with the other ingredients of the formulation and not deleterious to the recipient thereof.
The compositions of the invention include those in a form especially formulated for oral, buccal, parenteral, inhalation or insufflation, implant or rectal administration.
Tablets and capsules for oral administration may contain conventional excipients such as binding agents, for example, syrup, acacia, gelatin, sorbitol, tragacanth, mucilage of starch or polyvinylpyrrolidone; fillers, for example, lactose, sugar, microcrystalline cellulose, maize-starch, calcium phosphate or sorbitol; lubricants, for example, magnesium stearate, stearic acid, talc, polyethylene glycol or silica; disintegrants, for example, potato starch or sodium starch glycollate, or wetting agents such as sodium lauryl sulphate. The tablets may be coated according to methods well known in the art. Oral liquid preparations may be in the form of, for example, aqueous or oily suspensions, solutions emulsions, syrups or elixirs, or may be presented as a dry product for constitution with water or other suitable vehicle before use. Such liquid preparations may contain conventional additives such as suspending agents, for example, sorbitol syrup, methyl cellulose, glucose/sugar syrup, gelatin, hydroxyethylcellulose, carboxymethyl cellulose, aluminium stearate gel or hydrogenated edible fats; emulsifying agents, for example, lecithin, sorbitan monooleate or acacia; non-aqueous vehicles (which may include edible oils), for example, almond oil, fractionated coconut oil, oily esters, propylene glycol or ethyl alcohol; solubilizers such as surfactants for example polysorbates or other agents such as cyclodextrins; and preservatives, for example, methyl or propyl p- hydroxybenzoates or ascorbic acid. The compositions may also be formulated as suppositories, e.g. containing conventional suppository bases such as cocoa butter or other glycerides.
For buccal administration the composition may take the form of tablets or lozenges formulated in conventional manner.
The composition according to the invention may be formulated for parenteral administration by injection or continuous infusion. Formulations for injection may be presented in unit dose form in ampoules, or in multidose containers with an added preservative. The compositions may take such forms as suspensions, solutions, or emulsions in oily or aqueous vehicles, and may contain formulatory agents such as suspending, stabilising and/or dispersing agents. Alternatively the active ingredient may be in powder form for constitution with a suitable vehicle, e.g. sterile, pyrogen-free water, before use.
For administration by inhalation the compounds according to the invention are conveniently delivered in the form of an aerosol spray presentation from pressurised packs, with the use of a suitable propellant, such as dichlorodifluoromethane, tirchlorofluoromethane, dichloro-tetrafluoroethane, carbon dioxide or other suitable propellants, such as dichlorodifluoromethane, trichlorofluoromethane, dichlorotetrafluoroethane, carbon dioxide or other suitable gases, or from a nebuliser. In the case of a pressurised aerosol the dosage unit may be determined by providing a valve to deliver a metered amount.
Alternatively, for administration by inhalation or insufflation, the compounds according to the invention may take the form of a dry powder composition, for example a powder mix of the compound and a suitable carrier such as lactose or starch. The powder composition may be presented in unit dosage form in, for example, capsules or cartridges of e.g. gelatin, or blister packs from which the powder may be administered with the aid of an inhaler or insufflator.
The composition according to the invention may also be formulated as a depot preparation. Such long acting formulations may be administered by implantation (for example subcutaneously or intramuscularly) or by intramuscular injection. Thus for example, the compounds of the invention may be formulated with suitable polymeric or hydrophobic materials (for example as an emulsion in an acceptable oil) or ion exchange resins, or as sparingly soluble derivatives, for example, as a sparingly soluble salt
The compositions according to the invention may contain between 0.1-99% of the active ingredient, conveniently from 30-95% for tablets and capsules and 3-50% for liquid preparations.
Compounds of general formula (I) enantiomers and salts thereof may be prepared by the general methods outlined hereinafter. In the following description, the groups R, R1, R2, A, Z, X and Y are as defined for the compounds of formula (I) unless otherwise stated.
Compounds of formula (I) and enantiomers thereof may be prepared by the cyclisation of a compound of formula (II) in which R12 is a carboxylic protecting group, R13 represents a bromine or iodine atom, R14 represents hydrogen or a nitrogen protecting group. 
Followed where necessary or desired by removal of one or more protecting groups.
In one embodiment of this process the reaction may be carried out using a catalytic amount of a Palladium (O) complex such as tetrakis(triphenylphosphine)palladium and a suitable organic base such as trialkylamine e.g. triethylamine or inorganic base, e.g. potassium carbonate.
The reaction is conveniently carried out in an aprotic polar solvent such as acetonitrile, dimethylformamide or in aprotic apolar solvent such as hydrocarbon (ie toluene, xilene, hexane) at a temperature within the range of 60xc2x0 C. to 150xc2x0 C. followed, where necessary or desired, by subsequent removal of the carboxyl protecting group R12 and any protecting group R14.
In a further embodiment of the process the reaction is carried out using a catalytic amount of a Pd(II) salt such as: palladium acetate or palladium dichloride in the presence of a suitable organic base such as trialkyl amine e.g. triethylamine and of a triarylphosphine such as triphenylphosphine.
The reaction is carried out in an aprotic solvent such as acetonitrile or dimethylformamide and preferably with heating followed, where necessary or desired, by subsequent removal of the carboxyl protecting group R12 and any nitrogen protecting group R14.
Compounds of formula (I) wherein Xxe2x80x94Y is a double bond may be regioselectively prepared by carring out the cyclisation reaction in an aprotic apolar solvent such as toluene in the presence of catalytic amount of a Palladium (O) complex such as tetrakis(triphenylphosphine)palladium and a suitable organic base such as trialkylamine e.g. triethylamine or inorganic base, e.g. potassium carbonate. Compounds of formula (I) wherein Xxe2x80x94Y is a single bond may be prepared by carring out the reaction the cyclisation reaction in an aprotic polar solvent (such as acetonitrile, dimethylformamide) in the presence of a catalytic amount of a Pd(II) salt such as: palladium acetate or palladium dichloride in the presence of a suitable organic base such as trialkyl amine e.g. triethylamine and of a triarylphosphine such as triphenylphosphine.
Suitable carboxyl protecting groups R12 for use in this reaction include alkyl, such as ethyl, trichloroalkyl, trialkylsilylalkyl, or arylmethyl groups such as benzyl, nitrobenzyl or trityl. Further convenient carboxyl protecting groups are those having a chiral group derived from chiral alcohols such as (+)-S-indanol, (+)-S-methyl mandelate, chiral (C1-4)alkyl lactate: i.e. (+)-R- or (xe2x88x92)-S-methly lactate, (+)-R-t-butyl lactate, (+)-R- or (-4thyl lactate, (xe2x88x92)-S4-isopropyl lactate, (xe2x88x92)-S-butyl lactate, (+)-R-isobutyl lactate or chiral aralkyl lactate (i.e. benzyl lactate), (xe2x88x92)-S-perillyl alcohol, (xe2x88x92)-methyl-(R)-3-hydroxy-2-methylpropionate, (xe2x88x92)-(R)-2-butanol, (xe2x88x92)-(S)-2-methyl-1-butanol. R12 is preferably an ethyl, benzyl group or a group derived from a chiral(C1-4) alkyl lactate alcohol (eg (+)-(R)-t-butyl lactate (xe2x88x92)-S-butyl lactate, (+)-R-isobutyl lactate alcohol).
When R14 is nitrogen protecting examples of suitable groups include alkoxycarbonyl e.g. t-butoxycarbonyl, arylsulphonyl e.g. phenysulphonyl or 2-trimethylsilylethoxymethyl. Compounds of formula (II) may be prepared from compound of formula (III) in which R12 is a carboxyl protecting group and R14 is hydrogen or a nitrogen protecting group as defined in formula (II) and R13 represents a bromine or iodine atom. 
by reaction with an appropriate phosphorus reagent capable of converting the group CHO into the group: 
followed, where necessary or desired, by removal of the carboxyl protecting group R12 and nitrogen protecting group R13. In one embodiment of this process the reaction may be carried out using a phoshorus ylide of formula (IV) 
wherein R15 is an alkyl or phenyl group.
The reaction is carried out in an aprotic solvent such as acetonitrile or dimethylformamide at a temperature ranging from xe2x88x9220xc2x0 C. to the reflux temperature of the solvent.
Compounds of formula (III) and (IV) are either known compounds or may be prepared by analogous methods to those used for known compounds. A convenient method for preparing compounds of formula (III) is reacting compound of formula (V) in which R12 is a carboxyl protecting group and R14 is hydrogen or a nitrogen protecting group as defined in formula (II) and R13 represents a bromine or iodine atom with an allyltintrihalide.(VI) followed by ozonization reaction 
The reaction conveniently takes place in a solvent such as hydrocarbon e.g. Toluene or halogenated hydrocarbon (e.g. dichloro methane at a temperature ranging from xe2x88x9278xc2x0 C. to room temperature). The ozonization may be carried out by passing a stream of ozone into a solution in the presence of dimethyl sulphide or triphenylphosphine in a suitable solvent such as halohydrocarbon (e.g dicholoromethane) at low temperature e.g. xe2x88x9278xc2x0 C.
Alternatively compounds (III) may be prepared by aldolic reaction of the imino compound (V), with the enol ether (VII), wherein R16 is a C1-4 alkyl group. 
The reaction may be carried out in a solvent such as methylene cloruro or acetonitrile in the presence of a Lewis acid such as Ytterbium triflate.
In any of the above reactions the carboxyl protecting group may be removed by conventional procedures known for removing such groups. Thus compounds where R12 is a benzyl, ethyl or (+)-R- or (xe2x88x92)-S-t-butyl lactate group may be removed by hydrolysis using an alkali metal hydroxide e.g. lithium hydroxide or sodium hydroxide in a suitable solvent such as ethanol or isopropanol, water or mixtures thereof, followed, where desired or necessary, by that addition of a suitable acid e.g. hydrochloric acid to give the corresponding free carboxylic acid.
In any of the above reactions the nitrogen protecting group may be removed by conventional procedures known for removing such groups, for example by acid or base hydrolysis. Thus when R14 is alkoxycarbonyl e.g. t-butoxycarbonyl or phenylsulphonyl it may be removed by alkaline hydrolysis using for example lithium hydroxide in a suitable solvent such as tetrahydrofuran or an alkanol e.g. isopropanol. Alternatively the alkoxycarbonyl group may be removed by acid hydrolysis.
Physiologically acceptable salts of compounds of formula (I) may be prepared by treating the corresponding acid with an appropriate base in a suitable solvent For example the sodium or potassium salt may be prepared by treating a solution of the corresponding acid of a compound of formula (I) with sodium or potassium 2-ethylhexanoate with alkali or alkaline metal hydroxide, or the corresponding carbonate or bicarbonate thereof. Alternatively alkali or alkaline metal salts may be prepared by direct hydrolysis of carboxyl protected derivatives of compounds of formula (I) with the appropriate alkali or alkaline metal hydroxide.
Metabolically labile esters of compounds of formula (I) may be prepared by esterification of the carboxylic acid group or a salt thereof or by trans esterfication using conventional procedures. Thus, for example, acyloxyalkyl esters may be prepared by reacting the free carboxylic acid or a salt thereof with the appropriate acyloxylalkyl halide in a suitable solvent such as dimethylformamide. For the esterifcation of the free carboxyl group this reaction is preferably carried out in the presence of a quaternary ammonium halide such as tetrabutylammonium chloride or benzyltriethylammonium chloride.
Specific enantiomers of the compounds of formula (I) may also be obtained from corrisponding racemic compounds of formula (I) using chiral HPLC procedure.
Alternatively the enantomers may be prepared by esterification of the corresponding racemic compounds of formula (I) with a suitable chiral alcohol, separating the resultant diastereomeric esters by conventional means e.g. chromatography or crystallisation followed by hydrolysis of the diastereomeric esters.
Suitable chiral alcohols for use in the process include (+)-S-indanol, (+)-S-methyl mandelate, chiral (C1-4)alkyl lactate: i.e. (+)-R- or (xe2x88x92)-S-methly lactate, (+)-R-t-butyl lactate, (+)-R- or (xe2x88x92)-4-ethyl lactate, (xe2x88x92)-4-isopropyl lactate, (xe2x88x92)-S-butyl lactate, (+)-R-isobutyl lactate or chiral aralkyl lactate (i.e. benzyl lactate), (xe2x88x92)-S-perillyl alcohol, (xe2x88x92)methyl-(R)-3-hydroxy-2-methylpropionate, (xe2x88x92)-(R)-2-butanol, (xe2x88x92)-(S)-2-methyl-1-butanol.
The diastereomeric esters of compounds of formula (I) may be prepared by conventional means such as reaction of the chiral alcohol with an activated derivative of a compound of formula (I) in an aprotic solvent such as ether e.g. tetrahydrofuran. The activated derivative of a compound of formula (I) may be prepared from compounds (I) using conventional means for preparing activated derivatives of a carboxylic acid groups such as those conveniently used in peptide synthesis.
A particularly convenient method of preparing the diastereomeric esters of compounds (I) is to prepare the activated derivative of compounds (I) in the presence of the chiral alcohol.
Thus for example racemic mixture of compounds (I) may be treated with the Mitsunobu combination of reagents, i.e. a dialkyl azodicarboxylate such as diethylazodicarboxylate and a triarylphosphine e.g. triphenylphosphine or trialkylphoshine (i.e. tributylphosphine) in the presence of the chiral alcohol.
The reaction conveniently takes place in the presence of a suitable solvent such as an ether (e.g. diethylether or tetrahydrofuran), a halohydrocarbon (e.g. dichloromethane) or a nitrile (e.g. acetontrile) or a mixture thereof at a temperature ranging from 0-30xc2x0 C.
The required single diastereomeric ester of compounds (I) may be obtained from the mixture thereof by conventional means, for example by the use of conventional chromatographic procedures such as preparative HPLC or by fractional crystallization. Alternatively the required single diastereomeric ester of compound of formula (I) may be obtained using a suitable chiral protecting group R12 as defined in formula (II). Specific enantiomers of compounds of formula (I) may be prepared from the corresponding single diastereomeric ester of compounds (I) by hydrolysis e.g. alkaline hydrolysis. Thus, for example, the hydrolysis may be carried using an alkali metal hydroxide e.g. sodium hydroxide or lithium hydroxide in a solvent such as an ether e.g. tetrahydrofuran and water.
Alternatively specific enantiomers of compounds of formula (I) may be prepared by stereoselective enzymatic hydrolysis of compounds of formula (VIII) 
Wherein R17 is a carboxyl protecting group Suitable carboxyl protecting group R17 for use in this reaction include C1-4 alkyl such as methyl, ethyl, propyl, butyl, or arylmethyl groups such as benzyl, nitrobenzyl or trityl. Suitable enzymes for use in this reaction are lipase enzymes such as Aspergillus niger (AP-12) ILipase-DS (Aspergillus niger, Amano), Candida rugosalipase (Amano), Candida cylindracea lipase (Amano), Alcaligenes sp. lipase, Rhizopus arrhizus lipase (Biotal), Wheat germ lipase (Sigma), Rhizopus niveus lipase (Amano), Promod 215-P protease (Biocatalyst), lipase E-7 Themogen), lipase E-17 (Thermogen). Further suitable enzymes which may be used in this reaction are porcine pancreatic lipase, alpha-chymotrypsin or trypsin. A particular preferred enzyme for use in this reaction is Aspergillus niger (AP-12).
Resting cells of the following organisms may also be used in this reaction Aspergillus ochraceus, Aspergillus niger, Aspergillus chevalied and Aspergillus cervinus. 
The reaction is conveniently carried out in an aprotic solvent such as DMSO, tetrahydrofuran in the presence of a suitable aqueous buffer (i.e. phosphate buffer or CaCl2. If required a solubilising agent such as Tween-80 may be added to the reaction mixture. In a further process the enzyme may be immobilized and the reaction is carried out in essentially xe2x80x9cneatxe2x80x9d water-saturated organic solvents such as methyl tert-butyl ether or tert-amyl alcohol.
In order that the invention may be more fully understood the following examples are given by way of illustration only.
In the Intermediates and Examples unless otherwise stated: Melting points (m.p.) were determined on a Gallenkamp m.p. apparatus and are uncorrected. All temperatures refer to xc2x0 C. Infrared spectra were measured on a FT-IR instrument. Proton Magnetic Resonance (1H-NMR) spectra were recorded at 400 MHz, chemical shifts are reported in ppm downfield (d) from Me4Si, used as internal standard, and are assigned as singlets (s), doublets (d), doublets of doublets (dd), triplets (t), quartets (q) or multiplets (m). Column chromathography was carried out over silica gel (Merck AG Darmstaadt, Germany). The following abbreviations are used in text EA=ethyl acetate, CH=cyclohexane, DCM=dichloromethane, THF=tetrahydrofuran, TFA=trifluoroacetic acid, TEA=triethylamine, DMF=dimethylformamide, Ac2O=acetic anhydride, PPA=polyphosphoric acid, DBU=1,8-diazobicyclo [5,4,0] undec-7-ene, DMSO=dimethylsulphoxide, IMS=mixture of Ethanol with 5% of methanol,LHDMS=Lithiumbis(trimethylsilyl)amide. DIPEA=diisopropylethylamine Tlc refers to thin layer chromatography on silica plates, and dried refers to a solution dried over anhydrous sodium sulphate; r.t. (RT) refers to room temperature. Enantiomer A or diastereoisomer A refer to a single enatiomer or a single diastereoisomer respectively whose absolute stereochemistry was not characterized.
Intermediate 1
(+)-Ethyl 2-(5-chloro-2-iodoanilino)-4-pentenoate
To a solution of 2-iodo 4 chloro aniline (9.1 g) in dry toluene (150 ml) ethyl glyoxylate (50% solution in toluene, 14.6 ml) and MgSO4 (2 g) were added and the resulting suspension was refluxed overnight. It was then filtered and concentrated to dryness under high vacuum at 50xc2x0 C. for 1.5 h. The resulting brown oil was dissolved in dichloromethane (150 ml) cooled to xe2x88x9278xc2x0 C. and TiCl4 (99.995% purity, 4 ml) was added via syringe.
The suspension was stirred 15 min at xe2x88x9278xc2x0 C., then allowed to warm to rt over 15 min before being cooled again to xe2x88x9278xc2x0 C. Allyltributyltin (17 ml) was then added and the reaction allowed to proceed for 1 h. The black solution was poured into 200 ml of ethyl acetate and washed first with a saturated solution of NH4Cl (2xc3x97150 ml), then with water and brine. The organic phase was dried and concentrated to give the crude product, which was purified by column chromatography (cyclohexane, then cyclohexanelethyl acetate 98/2) to give the title compound (10.4 g) as a colourless oil.
NMR (CDCl3) xcex4(ppm) 7.57 (d, 1H), 6.49 (dd, 1H), 6.45 (dd, 1H), 5.79 (m, 1H), 5.25 (dd, 1H) 5.24 (dd, 1H), 4.83 (d, 1H), 4.25 (q,2H), 4.13 (m, 1H), 2.66 (m, 2H), 1.30 (t, 3H).
Intermediate 2
(+)-Ethyl 2-(5-chloro-2-iodoanilino)-4-oxobutanoate
A solution of intermediate 1 (5.2 g) in dichloromethane (150 ml) was cooled to xe2x88x9278xc2x0 C. and ozone was bubbled through it until the clear solution became brick-red. At this point the flux of ozone was interrupted and the solution was purged with nitrogen for a few minutes. Triphenyl phosphine (7.1 g) was added and stirring continued for 1.5 h, without control of the temperature. The resulting solution was poured into 200 ml of ethyl acetate and washed first with a saturated solution of NH4Cl (2xc3x97150 ml), then with water and brine. The organic phase was dried and concentrated to give the crude product, which was purified by column chromatography (cyclohexanelethyl acetate 80/20) to give the title compound (2.4 g) as a colourless oil.
NMR (DMSO) xcex4(ppm) 9.80 (t, 1H), 7.57 (d, 1H), 6.55 (d, 1H), 6.51 (dd, 1H), 4.99 (d, 1H), 4.46 (m, 1H), 4.24 (q, 2H), 3.08 (m, 2H), 1.28 (t, 3H)
Intermediate 2a
(xc2x1) Ethyl 2-(3,5-dichloro-2-iodoanilino)-4-oxobutanoate
A solution of ethyl glyoxylate (50% solution in toluene, 1 ml) and MgSO4 (7 g) in toluene (30 ml) was refluxed in Dean-Stark apparatus for 0.5 hrs.
Then, 3,5,-chloro-2iodoaniline was added, and the mixture refluxed for 1 hr. Then mixture was cooled, filtered througt celite to eliminate the MgSO4, and concentrated. The resulting brown oil was dissolved in dichloromethane (15 ml) cooled to xe2x88x9278xc2x0 C. and Yb(OTf)3xH2O (0.186 g) was added. The suspension was stirred for 5 mins at xe2x88x9278xc2x0 C., then the vinyloxytrimethylsilane (0.29 g) was added and the temperature was risen to 20xc2x0 C. After 1 hr at that temperature a saturated solution of NH4Cl (20 cc) was added followed by ethyl acetate (30 ml). The organic phase was washed with brine (20 ml) and dried over sodium sulphate and concentrated to give the crude product, which was purified by column chromatography (cyclohexane, then cyclohexane/ethyl acetate 85/15) to give the title compound (0.562 g) as a colourless oil.
NMR (CDCl3) xcex4(ppm) 9.65 (s, 1H), 7.00 (d, 1H), 6.70 (d, 1H), 5.60 (d, 1H), 4.80 (m, 1H) 4.10 (q, 2H), 3.10 (m, 2H), 1.15 (t, 3H).
Intermediate 3
Tributyl (2-oxo-1-phenylpyrrolidin-1-yl)phosphonium bromide
N,N Nxe2x80x2Nxe2x80x2-Tetramethylethylene diamine (23.3 ml) was added to a solution of N-phenylpyrrolidinone (5 g) in dichloromethane (50 ml). The solution was cooled to 0-5xc2x0 and trmethylsilyl triflate (8.4 ml) was added over ca 20 mins maintaining the temperature in the range 0-5xc2x0. The resultant solution was stirred for 10 mins and a solution of pyridinium bromide perbromide (13 g) in acetonitrile (20 ml) was added over ca 20 mins maintaining the temperature in the range 0-10xc2x0. The resultant suspension was stirred at 0-5xc2x0 for ca 60 mins. Aqueous sodium bicarbonate solution (50 ml) was added, cautiously. The mixture was stirred for ca 5 mins and the layers are separated. The aqueous phase was diluted with water (20 ml) and back extracted with dichloromethane (20 ml). The combined organic phases were washed with further sodium bicarbonate solution (50 ml), 2M hydrochloric acid (2xc3x9750 ml) and water (50 ml), back extracting each wash with dichloromethane (10 ml). The organic solution was dried (MgSO4) and concentrated on a rotavapor. The red/brown solid was stirred with ethyl acetate (50 ml) and warmed to give a solution which was then cooled and tributylphosphine (8.5 ml) was added. The solution was heated to reflux and maintained at reflux for 2.5 hours. The solution was allowed to cool to room temperature and was then cooled to 0-5xc2x0. The resulting suspension was aged at 0-5xc2x0 for ca 60 min. The product was isolated by vacuum filtration and then washed with ethyl acetate:t-butylmethylether (1:1, 40 ml) and dried in a vacuum oven at 45xc2x0 to give the title compound as a white crystalline solid (10.12 g), mp 127-128xc2x0.
Intermediate 4
(xc2x1) E-Ethyl 2-(5-chloro-2-iodoanilino)-4-(2oxo-1-phenyl-3-pyrrolidinylidene) butanoate (4a);(1)-Z-Ethyl 2(5-chloro-2-iodoanilino)-4-(2-oxo-4-phenyl-3-pyrrolidinylidene)butanoate(4b)
To a solution of intermediate 2 (2.4 g) in acetonitrile (100 ml) at r.t. intermediate 3(3.7 g) and DBU (13 ml) were added and stirring was continued overnight at xe2x88x9220xc2x0 C. The crude solution was poured into 200 ml of ethyl acetate and washed with a saturated solution of NH4Cl (2xc3x97150 ml), then with water and brine. The organic phase was dried and concentrated to give the crude product as a 4/1 mixture of 4a/4b compounds. Purification by column chromatography (cyclohexane/ethyl acetate 80/20) gave the title 4a (2.16 g) and the 4b (0.5 g) compounds as colourless oils.
Intermediate 4a
NMR (CDCl3) xcex4(ppm) 7.72 (d, 2H), 7.56 (d, 1H), 7.38 (t, 2H), 7.16 (t, 1H), 6.6 (m, 1H), 6.50 (dd, 1H), 6.49 (d, 1H), 4.88 (d, 1H), 4.26 (m, 3H), 3.87 (t, 2H), 2.79 (m, 4H), 1.30 (t, 3H)
Intermediate 4b
NMR (CDCl3) xcex4(ppm) 7.69 (d, 2H), 7.52 (d, 1H), 7.38 (t, 2H), 7.17 (t, 1H), 6.47 (d, 1H), 6.44 (dd, 1H), 5.98 (m, 1H), 5.00 (d, 1H), 4.22 (m, 2H), 4.13 (m, 1H), 3.84 (t, 2H), 3.2-3.6 (m, 2H), 2.85 (m, 2H), 1.26 (t, 3H)
Intermediate 5
(1R)-2-(tert-butoxy)-1-methyl-2-oxoethyl-2-(5-chloro-2-iodoanilino)-4-pentenoate (5a) and (1R)-2-(tert-butoxy)-4ethyl-2-oxoethyl-2-4-chloro-2-iodoanilino)-4-pentenoate (6b)
A solution of intermediate 1tert-butyl-(R)-2(oxoacetoxy)-2-methyl acetate (4.1 g) in toluene (200 ml) was refluxed in a Dean-Stark apparatus for 2 hrs. After cooling to room temperature, 5-chloro-2-iodoaniline (4.3 g) was added, and the solution refluxed in the presence of MgSO4 for 3 hrs. The clear solution was cooled, filtered through cotton to eliminate the MgSO4, concentrated to dryness and re-dissolved in dichloromethane (150 ml). The solution was cooled to xe2x88x9278xc2x0 C., and TiCl4 (1.9 ml) was added slowly from a syringe. After 15 min, allyl tributyltn (7.9 ml) was added, and the resulting black suspension was stirred for 1 hr. It was then poured onto ethyl acetate (300 ml), and saturated NH4Cl (150 ml) was added. The organic phase was separated, washed with water and brine, dried and concentrated. Final purification by column chromatography (cyclohexanefethyl acetate 95/5) afforded the title compound (4.1 g) (65/35 mixture of diastereomers) as a colourless oil (7.01 g).
NMR (CDCl3) xcex4(ppm) 7.54 (1H), 6.46 (dd, 1H), 5.86 (m, 1H, 5.3-5.2 (m, 2H), 5.03 (m, 1H), 4.77 (bd, 1H), 4.16 (m, 1H), 2.8-2.68 (m, 2H), 1.50 (d, 3H), 1.45 (s, 9H)
Intermediate 5a
(1R)-2-(ter-butoxy)-1-methyl-2-oxoethyl-2-(5-chloro-2-iodoanilino)-4-pentenoate
To a solution of allyltributyl tin (3.3 g) in dry DCM (100 ml) a 1M solution in DCM of SnCl4 (10 ml) was added at xe2x88x9278 C. The mixture was stirred for 20 min, then intermediate 2-[2-(5-Chloro-2-iodo-phenylimino)-acetoxy]-1-(R)-methyl-acetic acid terbutyl ester (2.39 g) in dry DCM (50 ml) was added. The reaction was allowed to react at xe2x88x9278 C. for 20 min, then a saturated solution of NH4Cl was added and the resulting mixture was extracted with ethyl acetate (2xc3x97200 ml). The organic layer was washed with a solution of KF 10% in water, then diethyl ether was added and the resulting solid was filtered.
The solution was dried and evaporated under vacuum. Final purification by flash chromatography (CH/EA 95:5) give the title compound as pure diastereomer as a colourless oil (1.3 g).
NMR (CDCl3): 7.55 (d, 1H); 6.47 (d, 1H); 6.43 (d, 1H); 5.88 (m, 1H); 5.27 (m, 2H); 5.05 (q, 1H); 4.78 (d, 1H); 4.18 (m, 1HO; 2.74 (m, 2H); 1.52 (d, 3H); 1.67 (s, 9H).
IR (CDCl3): 3379, 1740
Intermediate 6
(1R)-2-(tert-butoxy)-1-methyl-2-oxoethyl-2-(5-chloro-2-iodoanilino)-4-oxobutanoate (6a) and (1R)-2(tert-butoxy)-1-methyl-2oxoethyl-2-(5-chloro-2-iodoanilino)-4-oxobutanoate (6b)
A solution of intermediate 5 (7.1 g) in dichloromethane (200 ml) was cooled to xe2x88x9278xc2x0 C. and ozone was bubbled through it until the solution turned red. Triphenylphosphine (8 g) was then added, and the reaction allowed to stir for 2 hrs, without control of the temperature. The crude mixture was evaporated to dryness and purified repeatedly by column chromatography ((cyclohexanelethyl acetate 85/15) to afford the title compound 6a (2.75 g) and 6b(0.87 g) as colourless oils.
Compound 6a
NMR (CDCl3) xcex4(ppm) 9.85 (t, 1H), 7.57 (d, 1H), 6.58 (d, 1H), 6.51 (dd, 1H), 5.04 (q, 1H), 4.96 (d, 1H), 4.62 (m, 1H), 3.13 (dd, 2H), 1.55-1.42 (m, 12H)
IR (CDCl3) (cmxe2x88x921) 1740
Compound 6b
NMR (CDCl3) xcex4(ppm) 9.81 (t, 1H), 7.57 (d, 1H), 6.60 (d,1H), 6.52 (dd, 1H), 5.02 (q, 1H), 4.95 (d, 1H), 4.55 (m, 1H), 3.11 (m, 2H), 1.55-1.43 (m, 12H).
IR (CDCl3) (cmxe2x88x921) 1740
Intermediate 6a
(1R)-2-(tert-butoxy)-1-methyl-2-oxoethyl-2-(5-chloro-2-iodoanilino)4-oxobutanoate
The title compound was obtained starting from intermediate 5a following the same procedure described for intermediate 6.
Intermediate 7
(E)-(1R)-2-(tert-butoxy)-1-methyl-2oxoethyl 2-(5chloro-2-iodoanilino)-4-(2-oxo-1-phenyl-3-pyrrolidinylidene)butanoate (diastereoisomer A)
To a solution of intermediate 6a (2.7 g) in acetonitrile (60 ml) 2b(3 g) and DBU (1 ml) were added and the mixture was reacted at xe2x88x9220xc2x0 C. overnight. It was then taken up with ethyl acetate (300 ml) and washed with 1N HCl, water and brine, dried and concentrated. Final purification by column chromatography (cyclohexane/ethyl acetate 85/15) afforded the title compound (2.1 g) as a white solid.
m.p. 36-39xc2x0, [xcex1]D 22xc2x0 (c=0.160% w/v in DMSO)
NMR (CDCl3) xcex4(ppm) 7.72 (d, 2H), 7.55 (d, 1H), 7.38 (t, 2H), 7.15 (t, 1H), 6.66 (m, 1H, 6.49 (dd, 1H), 6.48 (d, 1H), 5.05 (m, 1H, 4.81 (d, 1H), 4.30 (m, 1H), 3.87 (t, 2H), 3.0 (m, 2H), 2.75 (m, 2H), 1.51 (d, 3H), 1.45 (s, 9H).
Intermediate 8
(xe2x88x92)-(1R)-2-tert-butoxy)-1-methyl-2-oxoethyl 7-chloro-4-(1-phenyl-xcex943-pyrrolin-2-one-3yl)-1,2,3,4-tetrahydroquinoline-2-carboxylate (8a)
(xe2x88x92)7-chloro-4-(2-oxo-1-phenyl-3-pyrrolidinylidene)-1,2,3,4-tetrahydro-2-quinoline2-carboxylic acid, [1-(R)-(1-tert-butoxycarbonyl)]ethyl ester (8b)
To a solution of intermediate 7 (2.1 g) in DMF (40 ml) Pd(PPh3)4 (0.393 g) and triethylamine (0.95 ml) were added and the mixture was heated to 150xc2x0 C. for 1 hr. The crude solution was taken up with ethyl acetate and washed with 1N HCl, water and brine, dried and evaporated. Final purification by column chromatography (cyclohexane/dichloromethanelethyl acetate 50/40/10) afforded the title compound 8a (0.7 g) as a white solid.
m.p.=69-73xc2x0 C.
[xcex1]Dxe2x88x9270.1xc2x0 (c=0.190% w/v in DMSO)
NMR (DMSO) xcex4(ppm) 7.80 (m, 2H), 7.39 (m, 2H), 7.12 (m, 1H), 6.82 (d, 1H), 6.77 (d, 1H), 6.70 (m, 1H), 6.49 (dd, 1H), 6.46 (bs, 1H), 4.93 (q, 1H), 4.49 (m, 2H), 4.02 (m, 1H), 3.87 (m, 1H), 2.44 (m, 1H), 2.00 (m, 1H), 1.39 (s, 9H), 1.38 (d, 3H).
IR (Nujol) (cmxe2x88x921) 3380, 1741, 1681, 1601 and the title compound 8b (0.8 g) as a yellow solid.
m.p.=59-64xc2x0 C.
[xcex1]Dxe2x88x9276.2xc2x0 (c=0.510% w/v in DMSO)
NMR (DMSO) xcex4(ppm) 7.73 (m, 2H), 7.36 (m, 2H), 7.21 (d, 1H), 7.11 (m, 1H), 6.98 (da,1H, 6.75 (d, 1H), 6.57 (dd, 1H), 4.70 (q, 1H), 4.24 (m, 2H), 3.84 (m, 1H), 3.75 (m, 1H), 3.18 (m, 1H), 3.05 (m, 1H), 2.94 (m, 1H), 1.25 (s, 9H), 1.23 (d, 3H)
Intermediate 9
(xc2x1)-E-Ethyl 2-(5-chloro-2-iodoanilino)4-(2oxo-1-phenyl piperidinylidene) butanoate
To a solution of tributyl-3-(1-phenyl-2-piperidinone)phosphonilum bromide (0.83 g) in acetonitrile (20 ml) DBU (0.27 ml) was added and after 15 min a solution of the intermediate 2 (0.35 g) in acetonitrile (20 ml). The reaction mixture was stirred for 30 min, then diluted with ethyl acetate and washed with a 1N solution of HCl and brine. The organic phase was dried and concentrated to give the crude product which was purified by flash column chromatography to obtain the title compound (0.29 g) as pale yellow foam.
NMR (CDCl3) xcex4(ppm) 7.56 (dd, 1H), 7.38 (dd, 2H), 7.27 (dd, 2H), 7.24 (t, 1H), 6.93 (t, 1H), 6.50-6.47 (m, 2H), 4.85 (d, 1H), 4.25 (q, 2H), 4.22 (m, 1H), 3.71 (m, 2H), 2.76, (m, 2H), 2.59 (m, 2H), 2.01 (m, 2H), 1.29 (t, 3H)
Intermediate 10
(xc2x1)-Ethyl 2-(5-chloro-2-iodoanilino)-4-(2-oxo-1-(pyridin-3-yl)-pyrrolidin-3-ylidene)butanoate
To a solution of the (1-(pyridin-3-yl)-2-oxo-pyrrolidin-3-yl)tributylphosphonium bromide (0.93 g) in acetonitrile (10 ml) DBU (0.22 ml) was added and after 10 min a solution of the intermediate 2 (0.46 g) in acetonitrile (10 ml). The reaction mixture was stirred for 3 hr. then diluted with ethyl acetate and washed with a saturated solution of NH4Cl and brine. The organic phase was dried and concentrated to give the crude product which was purified by flash column chromatography to obtain the title compound (0.47 g) as a mixture of E/Z isomer (80/20).
MS (m/z) 526
Intermediate 11
(xc2x1)-E-Ethyl 2-(3,5-dichloro-2-iodoanilino)-4-(2-oxo-1-phenyl-3-pyrrolidinylidene)butanoate (11a);(xc2x1)-Z-Ethyl 2-(3,5-dichloro-2-iodoanilino)-4-(2-oxo-1-phenyl-3-pyrrolidinylidene)butanoate (11b)
To a solution of intermediate 2a in acetonitrile (10 ml) at r.t 2b (0.726 g) and DBU (0.33 ml) were added and stirring was continued overnight at xe2x88x9220xc2x0 C. The crude solution was poured into 20 ml of ethyl acetate and washed first with a saturated solution of NH4Cl (2xc3x9715 ml), then with water and brine. The organic phase was dried and concentrated to give the crude product as a 4/1 mixture of Z/E isomers. Purification by column chromatography (cyclohexanelethyl acetate 85/15) gave the title compound 11a (0.498 g) and the title compound 11b (0.122 g) as colourless oils.
intermediate 11a
NMR (CDCl3) xcex4(ppm) 7.78 (d, 2H), 7.39 (t, 2H), 7.16 (t, 1H), 6.90 (d, 1H), 6.58 (m, 1H), 6.36 (d, 1H), 5.22 (d, 1H), 4.26 (m, 3H), 3.87 (t, 2H), 2.79 (m, 4H), 1.30 (t, 3H)
IR (CDCl3) (cmxe2x88x921) 3370, 1738, 1697, 1671.
MS (m/z) 559.
intermediate 11b
NMR (CDCl3) xcex4(ppm) 7.69 (d, 2H), 7.38 (t. 2H), 7.17 (t, 1H), 6.84 (d, 1H), 6.34 (d, 1H), 5.96 (m, 1H), 5.34 (d, 1H), 4.22 (m, 2H), 4.12 (m, 1H), 3.84 (t, 2H), 3.63-3.27 (m, 2H), 2.85 (t, 2H), 1.26 (t, 3H)
IR (CDCl3) (cmxe2x88x921) 1733, 1685.
MS (m/z) 559.
Intermediate 12
-(1R)-2-(tert-butoxy)-1-methyl-2-oxoethyl 2-(5-chloro-2-iodoanilino)-4-(2oxo-1-phenyl-3-pyrrolidinylidene)butanoate (diastereoisomer
To a solution of intermediate 6b (0.87 g) in acetonitrile (20 ml) tributyl-3-(N-phenyl-1-pyrrolidonyl)phosphonium bromide (1.6 g) and DBU (0.33 ml) were added and the mixture was reacted at xe2x88x9220xc2x0 C. overnight. It was then taken up with ethyl acetate (100 ml) and washed with 1N HCl, water and brine, dried and concentrated. Final purification by column chromatography (cyclohexanelethyl acetate 85/15) afforded the title compound (0.47 g) as a white solid oil.
m.p.=38-42xc2x0 C.
NMR (CDCl3) xcex4(ppm) 7.72 (d, 2H), 7.55 (d, 1H), 7.38 (t, 2H), 7.16 (t, 1H), 6.60 (m, 1H), 6.56 (d, 1H), 6.49 (dd, 1H). 5.03 (q, 1H), 4.80 (d, 1H), 4.33 (m, 1H), 3.88 (t, 2H), 2.9 (m, 2H), 2.75 (m, 2H), 1.48 (d, 3H), 1.44 (s, 9H).
IR (CDCl3) (cmxe2x88x921) 3375, 1738, 1693, 1665
Intermediate 13
-(1R)-2-(tert-butoxy)-1-methyl-2-oxoethyl 7-chloro-4-(1-phenyl-xcex943-pyrrolin-2-one-3yl)-1,2,3,4-tetrahydroquinoline-2-carboxylate (diastereoisomer B)
To a solution of intermediate 12 (0.46 g) in DMF (8 ml) Pd(PPh3)4 (0.043 g) and triethylamine (0.21 ml) were added and the mixture was heated to 150xc2x0 C. for 1 hr. The crude solution was taken up with ethyl acetate and washed with 1N HCl, water and brine, dried and evaporated. Final purification by column chromatography (cyclohexane/dichloromethane/ethyl acetate 50/40/10) afforded the title compound (0.114 g) as a white solid.
m.p.=62-67xc2x0 C.
NMR (DMSO) xcex4(ppm) 7.79 (m, 2H). 7.38 (m, 2H), 7.11 (t, 1H), 6.81 (d, 1H), 6.77 (d, 1H), 6.70 (d, 1H), 6.55 (bs, 1H), 6.48 (dd, 1H), 4.90 (q, 1H), 4.5 (m, 2H), 3.99 (m, 1H), 3.84 (t, 1H), 2.35 (m, 1H), 2.02 (m, 1H), 1.39 (s, 12H).
Intermediate 14
2,4dibromo-N-(4-(tert-butoxycarbonylamino)phenyl)-butyramide
To the derivative 2,4- dibromobutyryl bromide (3.1 g) in dry dichloromethane (60 ml) pyridine (3.2 ml) was added, the mixture was kept at 0xc2x0 C. under a nitrogen atmosphere for 10 minutes and then the N-t-butoxy carbonyl-1,4 phenylene diamine (2.08 g) was dropped. After 1 hour the mixture was poured into a saturated solution of NH4Cl (200 ml) extracted with EA (3xc3x97150 ml) and the organic phase washed with brine (200 ml), dried and concentrated in vacuum, the crude was purified by flash chromatography (eluting with CH/EA 80:20) to give of the title compound as a yellow foam (3.5 g ). T.I.c. CH/EA 8:2, Rf=0.53.
1H-NMR: 7.89 (sa); 7.44 (d); 7.35 (d); 6.46 (sa); 4.66 (dd); 3.60 (m); 2.76(m); 2.55(m); 1.51(s).
Intermediate 15
3-bromo-1-(4-(tert-butoxycarbonylamino)phenyl-2-oxo-pyrrolidine
To a solution of intermediate 14 (3.5 g) in dry THF (50 ml) cooled (0xc2x0 C.), a solution of LHMDS (9.6 ml of a 1M solution in tetrahydrofuran) was added drop-wise. The mixture was stirred under nitrogen until the temperature reached r.t for 2 hours. Then it was quenched into a saturated solution of NH4Cl (200 ml) extracted with EA (3xc3x97150 ml) and the organic extracts were washed with brine (200 ml), dried and concentrated in vacuum. The mixture was purified by flash chromatography (eluting with CH/EA 8:2) to give the title compound (2.6 g). T.I.c. CHIEA 8:2, Rf=0.31. 1H-NMR: 7.57 (d); 7.39 (d); 6.49 (sa); 4.59 (m); 4.03 (m); 3.81 (m); 2.73 (m); 2.46 (m); 1.53(s).
Intermediate 16
(+/xe2x88x92)-Z-Ethyl2-(5chloro-2-iodoanilino)-4-(2-oxo-1-(4-tert-butoxycarbonylamino)phenyl-pyrrolidin-3-ylidene)butanoate
A solution of intermediate 15 (2.6 g) in dry DMF (100 ml) and tributylphosphine was refluxed at 110xc2x0 C. under a nitrogen atmosphere for 4 h, until reaction completion (TLC). The mixture was concentrated in vacuum to give the crude1-(4-tert-butoxycarbonylamino)phenyl-2-oxo-pyrrolidin-3-yl-tributylphosphonium bromide (1.75 g) which was dissolved in dry CH3CN (100 ml) was cooled at xe2x88x9230xc2x0 C. and stirred under a nitrogen atmosphere, then DBU (0.44 ml) and intermediate 2 (1.0 g) were added. The mixture was stirred for 1 h then was poured into a saturated solution of NH4Cl (200 ml) extracted with EA (3xc3x97150 ml) and the organic extracts were washed with brine (200 ml), dried and concentrated in vacuum to give a yellow oil which was purified by flash chromatography (eluting with CH/EA 80:20) to give the title compound (0.085 g) as a white solid.
T.I.c. CH-EA (7:3), Rf=0.23 IR: 1727 and 1695 (Cxe2x95x90O) cmxe2x88x921. 1H-NMR: 7.64 (d); 7.53 (d); 7.38 (d); 6.48 (d); 6.47 (sa); 6.45 (dd); 5.97(m); 5.02(d); 4.23 (m); 4.14 (m); 3.8(t); 3.6 (m); 3.3 (m); 2.85 (m); 1.53(s); 1.27(t).
Intermediate 17
(xc2x1)-Z-Benzyl 2-(5-chloro-2-iodoanilino)-4-(2,5-dioxo-1-phenyl-imidazolidinylidene)butanoate
To a solution of the derivative N-(phenylaminocarbonyl)xcex1-phosphonoglycine-trimethyl ester (0.1 g) in acetonitrile (10 ml) DBU (0.1 ml) was added and after 10 min a solution of the (+/xe2x88x92)-2-(5-Chloro-2-iodo-phenylamino)-4-axo-butyric acid benzyl ester (0.1 g) in acetonitrile (2 ml). The reaction mixture was stirred for 1xc2xd hr, then diluted with ethyl acetate and washed with a 1N solution of HCl and brine. The organic phase was dried and concentrated to give the crude product which was purified by flash column chromatography to obtain the title compound (0.065 g)
NMR (DMSO) xcex4(ppm) 10.80 (s, 1H), 7.65 (d, 1H), 7.7-7.3 (m, 10H), 6.75 (d, 1H), 6.55 (dd, 1H), 5.70 (t, 1H), 5.20 (s, 2H), 5.07 (d, 1H), 4.72 (m, 1H, 2.86 (t, 2H
IR (Nujol) (cmxe2x88x921) 3339, 3160, 1768, 1721, 1691
Intermediate 18
(xc2x1)-Benzyl 7chloro-4-(2,5-dioxo-1-phenyl-imidazolidin-4-ylidene)-1,2,3,4-tetrahydro-2-quinolinecarboxylate
To a solution of intermediate 17 (0.065 g) in DMF (5 ml) Pd(PPh3)4 (16 mg) and TEA (0.05 ml) were added and the resulting solution was heated to 110xc2x0 C. for 1 h. The crude solution was poured into ethyl acetate and washed with a 1N solution of HCl and brine. The organic phase was dried and concentrated to give the crude product which was purified by flash column chromatography to obtain the title compound (0.015 g) as yellow powder.
m.p. greater than 220xc2x0 C.
NMR (DMSO) xcex4(ppm) 10.5 (s, 1H), 7.5-7.2 (m, 11H), 7.16 (bd, 1H), 6.75 (d, 1H, 6.58 (dd, 1H, 5.2-5.01 (dd, 2H), 4.40 (m, 1H), 4.25 (dd, 1H), 2.83 (dd, 1H).
IR (Nujol) (cmxe2x88x921) 3378, 1752, 1728, 1704
Intermediate 19
2-[2-(5-chloro-2-iodo-phenylimino)-acetoxy]-1-(R)-methyl-acetic acid isobutyl ester
To a solution of acrylic acid 1-isobutoxycarbonyl-1R)-methyl-methyl ester (3.7 g) in THF/H2O OsO4 4% in H2O (4 ml) was added. The black suspension was then treated with NaIO4 (10.5 g) by portions. After 5 hrs, the solution was taken up with ethyl acetate (2xc3x9750 ml) and washed with water (2xc3x9750 ml). The organic phase evaporated under vacuum and the crude mixture was purified by flash chromatography (CH/EA 1:1) to afford 2-(2-Oxo-acetoxy)-1-(R)-methyl-acetic acid isobutyl ester as colourless oil (3 g). 24.8 g of 2-(2-Oxo-acetoxy)-1-(R)-methyl-acetic acid isobutyl ester was dissolved in toluene (1000 ml) and refluxed in a Dean-Stark apparatus for 2 hrs. After cooling to room temperature, 5chloro-2-iodoaniline (22 g) was added, and the solution refluxed in the presence of MgSO4 for 3 hrs. The clear solution was cooled, filtered through cotton to eliminate the MgSO4, concentrated to dryness to obtain the title compound (38 g) as a yellow oil.
NMR (CDCl3) xcex4(ppm) 7.83 (1H, d), 7.79 (s 1H), 7.02(dd,1H),6.96 (d, 1H), 5.373 (q 1H), 4.00 (m, 2H), 2.00 (m, 1H), 1.67 (d, 3H), 0.96 (2d, 6H)
IR (CDCl3): 1749, 1730
Intermediate 20
2-(5Chloro-2-iodo-phenylamino)-4-oxo-butyric acid 1-isobutoxycarbonyl-1(R)-methyl-methyl ester (20a and 20b)
A solution of intermediate 19 (38 g) in toluene (1 ml) was cooled to xe2x88x9220xc2x0 C. and Yb(OTf)3 (16.5 g) was added and, after a few minutes, vinyloxy trimethylsilane (12.5 g) dissolved in toluene (50 ml) was added drop-wise. The bath was removed and the reaction allowed to stir for 2 hrs. The crude mixture was taken up with ethyl acetate (500 ml) and the organic phase was washed with a saturated solution of ammonium chloride (300 ml) and evaporated. Then, the mixture was purified by column chromatography (cyclohexane/ethyl acetate 85/15) to afford the title compounds 20a (14 g) and 20b (4 g) as colourless oils.
Intermediate 20a
NMR (CDCl3) xcex4(ppm) 9.85 (s, 1H), 7.57 (d, 1H), 6.58 (d, 1H), 6.51 (dd, 1H), 5.19 (m, 1H), 4.97 (d, 1H), 4.63 (m, 1H), 3.93 (m, 2H), 3.24-3.04 (m, 2H, 1.94 (m, 1H), 1.53 (d, 3H), 0.93 (dt, 3H); 0.91 (d, 3H).
IR (CDCl3) (cmxe2x88x921) 1742, 1740
Intermediate 20b
NMR (CDCl3) xcex4(ppm) 9.81 (s, 1H), 7.57 (d, 1H), 6.60 (d,1H, 6.52 (dd, 1H), 5.17 (m, 1H), 4.95 (d, 1H), 4.57 (m, 1H, 3.92 (m, 2H), 3.11 (m, 2H); 1.92 (m, 1H); 1.50 (d, 3H); 0.90 (d, 6H).
IR (CDCl3) (cmxe2x88x921) 3375, 1734
Intermediate 21
(E)-2-(5-Chloro-2-iodo-phenyl-pyrrolidin-3-ylidene)-butyric acid 1-isobutoxycarbonyl-1-(R) methyl-methyl ester
To a solution of intermediate 3 (14.45 g) in acetonitrile (200 ml) DBU (4.43 ml) was added at room temperature and the mixture was stirred for 10 min. The mixture was then cooled at xe2x88x9225xc2x0 C. and intermediate 31a (12.98 g) in 60 ml of CH3CN was added drop-wise in 15 min. Then the reaction was stirred at this temperature for 2 h. Then the mixture was taken up with ethyl acetate (100 ml) and the organic phase washed with a saturated solution of NH4Cl (150 ml), and HCl 2% (200 ml) and brine (2xc3x97200 ml). The solution was then dried and concentrated. Final purification by column chromatography (cyclohexane/ethyl acetate/CH2Cl2 7/0.5/2.5) afforded the title compound (11.04) as a white foam.
NMR (CDCl3) xcex4(ppm) 7.73 (m, 2H), 7.56 (d, 1H), 7.38 (t, 2H), 7.16 (m, 1H), 6.67 (m, 1H), 6.50(dd, 1H), 6.49 (s, 1H), 5.20 (q, 1H, 4.81 (d, 1H), 4.33 (m, 1H), 3.94 (d, 2H), 3.88 (t, 2H), 3.0-2.74 (m, 4H), 1.94 (m, 1H), 1.57 (d, 3H); 0.91 (d, 6H).
IR (CDCl3); 1696, 1670cmxe2x88x921
Intermediate 22
7-Chloro-4-(2-oxo-1-phenyl-pyrrolidin-3-ylidene)-1,2,3,4-tetrahydro-quinoline-2-carboxylic acid, [1-(R)-methyl-1-isobutoxcarbonyo-methyl ester (diastereolsomer A)
To a solution of intermediate 21 (9.55 g) in toluene (130 ml), Pd(PPh3)4 (3.52 g) and triethylamine (5.1 ml) were added in portions and the mixture was heated to 110xc2x0 C. for 3.5 hr. The crude solution was taken up with ethyl acetate (600 ml) and washed with NH4Cl and brine, dried and evaporated. Purification by column chromatography (cyclohexane/dichloromethane/ethyl acetate 6.5/3/0.5) afforded the title compound (6.08 g) as a yellow foam.
NMR (DMSO) xcex4(ppm) 7.71 (d, 2H), 7.35 (t, 2H), 7.20 (d, 1H), 7.11 (t, 1H), 7.00 (s,1H), 6.74 (d, 1H), 6.57 (dd, 1H, 4.89 (q, 1H), 4.24 (m, 2H), 3.84-3.60 (m, 4H), 3.2-2.8 (m, 3H), 1.70 (m, 1H), 1.24 (d, 3H); 0.73 (d, 6H).
IR (nujol): 3377, 1746, 1670
Intermediate 23
7Chloro-4-(2-oxo-1-phenyl-2,5-dihydro-1H-pyrrol-3-yl)-1,2,3,4-tetrahydroquinoline-2-carboxylic acid, [1-(R)-methyl-1-isobutoxycarbonyl]-methyl ester
To a solution of intermediate 22 (3.67 g) in DMF (50m1) Pd(PPh3)4 (0.340 g) and triethylamine (2 ml) were added and the mixture was heated to 110xc2x0 C. for 2 hrs. The crude solution was taken up with ethyl acetate (2xc3x97200 ml) and washed with NH4Cl and brine, dried and evaporated. Final purification by column chromatography (cyclohexane/dichloromethane/ethyl acetate 6.5/3/0.5) afforded the title compound (1.289 g) as a yellow foam.
NMR (DMSO) xcex4(ppm) 7.79 (d, 2H), 7.38(t, 2H), 7.11 (t, 1H), 6.79 (d, 1H), 6.57 (d, 1H), 6.74 (d, 1H); 6.47 (dd, 1H); 6.47 (m, 1H); 5.10 (q, 1H); 4.49 (m, 2H); 4.06 (m, 1H); 3.92-3.82 (m, 3H); 2.45 (m, 1H); 2.019 (m, 1H); 1.84 (m, 1H); 1.42 (d, 3H); 0.84 (d, 6H).
IR (nujol): 3375, 1749,1683.
Intermediate 24
2(3,6-Dichloro-2-iodo-phenylamino)-4-oxo-butyric acid 1-n-butoxycarbonyl-1(S)-methyl-methyl ester (24a and 24b)
To a solution of intermediate Acrylic acid 1-n-butoxycarbonyl-1-(S)-methyl-methyl ester(4.9 g) in THF/H2O (100 ml, 2/1) OsO4 4% in H2O (2.8 g) was added. The black suspension was then treated with NaIO4 (13 g) by portions. After 5 hrs, the solution was taken up with ethyl acetate (2xc3x9750 ml) and washed with water (2xc3x9750 ml). The organic phase evaporated under vacuum and the crude mixture was purified by flash chromatography (CH/EA 1:1) to afford the 2-(2-oxo-acetoxy)-1-(S)-methyl-acetic acid n-butyl ester as a colourless oil (4.85 g). (2.5 g) of which was dissolved in toluene (200 ml) and refluxed in a Dean-Stark apparatus for 2 hrs. After cooling to room temperature, 3,5-dichloro-2-iodoaniline (2.46 g) was added, and the solution refluxed in the presence of MgSO4 for 3 hrs. The clear solution was cooled, filtered through cotton to eliminate the MgSO4, concentrated to dryness to obtain (2-(2-(5-chloro-2-iodo-phenylimino)acetoxy]-1-(S)-methyl-acetic acid n butyl ester(4 g,) as a yellow oil.
A solution of such a yellow oil in CH3CN (70 ml) was cooled to xe2x88x9230xc2x0 C. and Yb(OTf)3 (2.1 g) was added and, after a few minutes, vinyloxy trimethylsilane (1.1 g) dissolved in CH3CN (20 ml) was added, drop-wise. The reaction was stirred for 10 min. The crude mixture was taken up with ethyl acetate (500 ml) and the organic phase was washed with a saturated solution of ammonium chloride (2xc3x9750 ml) and evaporated. Then, the mixture was purified by column chromatography (cyclohexane/ethyl acetate 90/10) to afford the title compounds 24a (1.4 g) and 24b (0.7 g) as colourless oils.
Intermediate 24a
NMR (CDCl3) xcex4(ppm) 9.84 (t, 1H), 6.92 (d, 1H); 6.45 (d, 1H); 5.33 (da, 1H); 5.17 (q, 1H); 4.60 (m, 1H); 4.14 (m, 2H); 3.34-3.06 (m, 2H); 1.6 (m, 2H); 1.52 (d, 3H); 1.37 (m, 2H); 0.93 (t, 3H).
IR (CDCl3) (cmxe2x88x921) 3370,1742
Intermediate 24b
NMR (CDCl3) xcex4(ppm) 9.80 (s, 1H), 6.92 (d, 1H); 6.47 (d, 1H); 5.3 (da, 1H); 5.15 (q, 1H); 4.55 (m, 1H); 4.14 (m, 2H); 3.13 (m, 2H); 1.57 (m, 2H); 1.49 (d, 3H); 1.34 (m, 2H); 0.91 (t, 3H).
IR (CDCl3) (cmxe2x88x921) 3370, 1744.
Intermediate 25
(E)-2-(3,5-Dichloro-2-iodo-phenylamino)-4-(2-oxo-1-phenyl-pyrrolidin-3-ylidene)-butyric acid 1-n-butoxycarbonyl-1-(S) methyl-methyl ester (diastereoisomerA)
To a solution of intermediate 2a (0.893) in acetonitrile (20 ml) DBU (0.25 ml) was added at room temperature and the mixture was stirred for 10 min. The mixture was then cooled at xe2x88x9225xc2x0 C. and intermediate 6b (0.8 g) in 10 ml of CH3CN was added drop-wise in 15 min. Then the reaction was stirred at this temperature for 30 min. Then the mixture was taken up with ethyl acetate (50 ml) and the organic phase washed with a saturated solution of NH4Cl (50 ml), and HCl 2% (10 ml) and brine (2xc3x9720 ml). The solution was then dried and concentrated. Final purification by column chromatography (cyclohexanelethyl acetate 8/2) afforded the title product (0.734 g) as a white foam.
NMR (CDCl3) xcex4(ppm) 7.72 (d, 2H), 7.39 (t, 2H), 7.17 (t, 1H); 6.92 (d, 1H); 6.60 (m, 1H); 6.43 (d, 1H); 5.16 (q, 1H); 5.14 (d, 1H); 4.34 (d, 1H); 4.15 (m, 2H); 3.89 (t, 2H); 2.75-2.4 (m, 4H); 1.60 (m, 2H); 1.53 (d, 3H); 1.34 (m, 2H); 0.91 (t, 3H).
IR (CDCl3); 3377,1744, 1697, 1672 cmxe2x88x921
Intermediate 26
5,7-Dichloro-4-(2-oxo-1-phenyl-2,5-dihydro-1H-pyrrol-3-yl)-1,2,3,4-tetrahydroquinoline-2-carboxylic acid, [1-(S)methyl-1-n-butoxycarbonyl]-methyl ester (26a)5,7-Dichloro-4-(2-oxo-1-phenylpyrrolidin-3-ylidene)-1,2,3,4-tetrahydro-quinoline-2-carboxalic acid, [1(S)-methyl-1-n-butoxycarbonyl]methyl ester (26b)
To a solution of intermediate 25 (0.734 g) in DMF (20 ml) Pd(OAc)2 (0.110 g) and triethylamine (0.37 ml) were added in portions, and the mixture was heated to 120xc2x0 C. for 3 hr. The crude solution was taken up with ethyl acetate (100 ml) and washed with NH4Cl and brine, dried and evaporated. Final purification by column chromatography (cyclohexane/dichloromethanelethyl acetate 7/2.5/0.5) afforded the title compound 26 a (0.35 g) and 26b(0.06 g) as a yellow foam.
Intermediate 26a
NMR (DMSO) xcex4(ppm) 7.80(d, 2H); 7.38 (t, 2H); 7.11 (t, 1H); 6.89 (d, 1H); 6.83 (s, 1H); 6.68 (d, 1H); 6.47 (d, 1H); 5.07 (q, 1H); 4.48 (m, 2H); 4.11 (m, 1H); 4.06 (t, 2H); 3.8 (dd, 1H); 2.3-1.8 (m, 2H); 1.52 (m, 2H); 1.40 (d, 3H); 1.54 (m, 2H); 1.3 (m, 2H); 0.84 (t, 3H).
IR (nujol): 3374, 1740, 1683 cmxe2x88x921 
Intermediate 26b
NMR (DMSO) xcex4(ppm) 7.69 (d, 2H); 7.39 (t, 2H); 7.33 (d, 1H); 7.15 (t, 1H); 6.71 (d, 1H); 6.62 (d, 1H); 4.72 (d, 1H); 4.40 (q, 1H); 4.40 (m, 1H); 3.94 (t, 2H); 3.76 (t, 1H); 3.60 (q, 1H); 3.12 (m, 1H; 2.35 (m, 1H); 2.21 (dd, 1H); 1.42 (m, 2H); 1.21 (m, 2H); 0.97 (d, 3H); 0.82 (t, 3H).
IR (nujol): 3377, 1746, 1684, 1594 cmxe2x88x921